Fluid mixing device



Sept. 21, 1965 l. RUBIN 3,207,484

FLUID MIXING DEVICE Filed June 20, 1963 //f y I f l 1 :1

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A yk/@25j u i AQ'ZMFM. /2/ i i? Ljnw United States Patent O 3,207,484 FLUID MIXING DEVICE Isadore Rubin, Grange, NJ., assigner to Industrial Process Engineers, Inc., Newark, NJ., a corporation of New Jersey Filed .lune 20, 1963, Ser. No. 289,336 3 Claims. (Cl. 259-4) This invention relates to a fluid mixing device and more particularly to such a device useful for producing substantially uniform mixtures of vaporous materials, such as ammonia vapor and air, or other materials whose mixture may be desired.

It is among the objects of the .present invention to pr-ovide a Huid mixing device which effects thorough mixing of fluids with relatively low pressure drop, which employs no moving parts and which is economical to construct and operate.

A further object of the invention is to provide a mixing device which is highly eflicient and produces substantially uniform iiuid mixtures.

In order to achieve these objects a fluid mixing device has been devised, comprising an elongated inner housing, an elongated outer housing enclosing at least a portion of the same, and a plurality of rows of transversely oriented hollow conduit elements mounted on and extending through the walls of the inner housing, the inner ends of which elements communicate with the interior of the inner housing and the outer ends of which communicate with the annular zonedefined between the inner and outer housings. A partition is provided intermediate the ends of the inner housing, dividing it into a first, inlet section and a second, outlet section, such that the separate fluids fed into the inlet section flow longitudinally thereof, pass into the annular z-one through the conduit elements extending through the walls of the inlet section, producing a helical flow pattern therein, and thereafter pass inwardly through the conduit element extending through the walls of the outlet section, producing a helical fluid flow pattern in the outlet section which is reversed with respect to that created in the annular space and thus effecting thorough mixing Iof the fluids prior to discharging the resulting mixture from the outlet end of the device.

The nature and objects of the present invention will be more fully apparent from a consideration of the following detailed description of a preferred embodiment thereof, taken in connection with the accompanying drawing in which:

FIGURE l is an isometric view of a preferred fluid mixing device, with the housing walls of the device partially broken away for clarification;

FIGURE 2 is a partially schematic longitudinal section through the fluid mixer of FIGURE l, in which each successive row of conduit elements is schematically illustrated by a d-ot-d-ash line;

FIGURE 3 is an end view of one of the rows .of conduit elements of the device, viewed in the direction of line 3-3 in FIGURE 2, and showing the iluid ow pattern leading from the inlet section to the annular region of the device; and

FIGURE 4 is a View similar to FIGURE 3, taken along the line 4-4 in FIGURE 2, showing the fluid ow pattern leading from the -annular region to the outlet section of the device.

In the drawing, in which the scale of various of the figures is `exaggerated for clarity, an embodiment of the iiuid mixing device of the invention is shown which may be employed for thoroughly mixing gaseous streams, such as streams of ammonia vapor and air, for producing thorough mixing with lo-w pressure drop. The device ICC includes an inner elongated tubular housing 11 into which the unmixed or partially mixed fluid stream or streams are fed through inlet end 12, and from which the uid mixture is removed through outlet end 13. As illustrated (FIGURES 1 and 2), the inlet and outlet ends of the device are conveniently provided with flanges 14 and 15, respectively, to facilitate attachment to other in-line equipment. An outer housing 16 is provided enclosing the inner housing 11 intermediate its ends. The outer yhousing includes an elongated tubular section 17 and frustoconical end portions 18 and 19 secured, as by welding, to the walls of the inner housing 11.

The inner and outer housings 11 and 16 define an annular region or zone 21 therebetween, into which extend a number of rows of transversely oriented hollow conduit elements. These rows of elements, which are schematically represented at 22, 23, 24, 25, 26, 27, 28 and 29 in F-IGURE 2, and rows 22 and 26 of which are shown in exaggerated scale in FIGURES 3 and 4, respectively, are mounted lon the walls of the inner housing 11. As best illustrated in FIGURES 3 and 4, each row of conduit elements includes a number of hollow pipe sections, e.g., pipe nipples, 31, 32, 33, 34 and 35 which are welded, as at points 36, to the tubular walls of the inner housing 11 transversely thereof. yIt will be noted that the inner end of each of the conduit elements thus opens into the interior of the inner housing 11 and the outer end of each such element opens into the annular zone.

In the embodiment illustrated, tive conduit elements are mounted radially of the inner housing with their axes in substantially coplanar relation, to define each row of elements. Referring to elements 31 and 35 (FIG- URE 3) as illustrative, the axes 37, 38 .of such elements are a-ngularly displaced by an angle A from their imaginary intersections on the outer surface of inner housing 11, with radii 39 and 41 extending from the central axis 42 of such housing. It has been found that particularly suitable mixing characteristics are obtained when t-he conduit elements are each oriented with the angle A equal to about 45.

Moreover, the individual conduit elements are desirably equi-spaced ang-ularly of the inner housing. When, as shown in FIGURE 3, iive conduit elements are utilized in each row, the angle B, between the radii 39 and 41 and the respective axes 37 and 38 of the individual conduit elements is about 72.

It will of course be understood that the angle A may be varied as desired and, depending upon the number of conduit elements in each row, the angle B may be varied in order to provide the preferred uniform angular displacement of the conduit elements of each row.

The successive rows of conduit elements are preferably arranged in `two sets, the rs-t constituted of rows 22, 24, 26 and 28 and the second, of rows 23, 25, 27 and 29, interposed between the rows of the iirst set. Each of the rows of elements of the first set possesses the configuration illustrated in FIGURES 3 and 4 for rows 22 and 26, whereas the elements of each row of the second set are angularly displaced'from the corresponding elements of the rst set, e.g., elements 31, 312, et-c., by a predetermined increment. It has been found that particularly suitable mixing characteristics are obtained when each of the conduit elements of the` rows of the second set are thus angularly displaced about 36; hence, if one considers radius 39 in FIGURE 3 as a center line with respect to which the individual conduit elements are fixed, each r-ow of the second set would possess the configuration shown in FIGURE 3 with the center line 39 rotated about 36.

A solid partition plate 43 is mounted intermediate the ends of the inner housing 11 separating a first or inlet section 44 of the inner housing, adjacent the inlet end i1.2, from a second or outlet section 45 of the inner housing, adjacent the outlet end 13.

The partition 43; the angularly displaced conduit elements in each of r-ows 22 to 25, extending through the walls of the inlet section 44; the angularly displaced conduit elements in each of rows 26 to 29, extending through the walls of the outlet section 45; and the angular displacement of the conduit elements in the adjacent rows of elements, determine a fluid ow path facilitating optimum mixing of mis-cible fluids fed through the device, while minimizing the resulting pressure drop.

In operation, as schematically illustrated by the arrows shown in FIGURES 1, 3 and 4, the iiuids fed into the inlet end 12 of the device flow longitudinally thereof through the inlet section 44 in the direction of arrows 46. The fluids thereafter pass outwardly of the inner housing 11 through the several conduit elements of rows 22 to 25 inclusive, the fluid owing in the direction of arrows 47 to produce a generally helical flow pattern through the annular region 21 between the inner and outer housings 11 and 16. As indicated at 48 in FIGURE 3, a generally counterclockwise helix is thus described in the annular zone 21, effecting a partial commingling and mixing of the fluids fed therethrough. It will be noted that such mixing is improved by the angular displacement of the conduit elements of the two sets of elements as described above.

' As the resulting fluid mixture passes through the portion of the annular region 21 in alignment with the outlet section 45 of the inner housing it flows into the outer ends of the individual conduit elements of rows 26 to 29 and is fed inwardly through such conduits into the outlet section 45. As may be best seen in FIGURE 4, this uid mixture ilows in the direction of arrows 49 and describes a helical fluid iiow pattern which is reversed from that initially formed in the annular region 21. The fluid mixture is then passed outwardly of the device through outlet end 13 thereof.

Hence, a generally` clockwise helical flow pattern 51 is produced inl outlet section 45, as compared with the generally counterclockwise helical flow pattern 48 induced in the annular region 2,1. It has been found that by thus achieving a reversal of helical flow pattern, employing reversed fluid ow through similarly oriented conduit elements, a thorough mixing of the individual iiuids passed through the device, may be achieved with a relatively small pressure drop.

The number of conduit elements in each row, and the number of rows of such elements in each of the inlet and outlet sections of the inner housing of the device, are dependent upon the volumetric rate of fluid iiow and the designed pressure drop through the device. It has been found preferable, in order to assure a minimum pressure drop, to provide the group of conduit elements mounted in each of the inlet and outlet sections in coniigur'ations such that the sum of the cross-sectional areas of each such group is substantially equal to the crosssectional area of the inlet end of the device. Moreover, in order to provide substantially uniform flow characteristics the adjacent rows of conduit elements of the two sets are angularly displaced from one another about 1/2 the angle between the adjacent conduit elements of each such row. Hence, while the embodiment of the invention described above includes four rows of conduit elements in each of the inlet and outlet sections, each row including five elements angularly displaced about 72 from one another and the corresponding members of the adjacent rows displaced about 36 from one another, it will be understood, for example, that a number (dependent upon the cross sectional area of the inlet end of the device) of rows of suitably dimensional conduit elements, each of which rows includes four uniformly angularly 4 disposed elements and the adjacent rows of which are displaced 45 from one another, may be mounted in each of the inlet and outlet sections, within the scope of the present invention.

It will also be appreciated that the configurations of the inlet and outlet ends 12 and 13, the length or diameter of the inner housing 11 or outer housing 16, or various other dimensions or shapes of the elements of the mixing device of the invention may be changed in accordance with the particular requirements of the specific installation in which the mixing device is to be incorporated.

Sincev these and other changes may be made in the disclosed embodiment of the invention without departing from the scope thereof, it will be understood that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

I claim: A

1. A fluid mixing device, which comprises:

(a) an elongated inner housing, having a iirst inlet end and a second outlet end;

(b) an elongated outer housing enclosing at least a portion of the inner housing to define an annular region therebetween;

(c) a plurality of rows of transversely oriented hollow conduit elements mounted on and extending through the walls of the inner housing, each of said elements communicating at its inner end with the interior of the inner housing and at its outer end with said annular region,

(i) each of said rows comprising a number of said elements whose axes are substantially co-planar and which are successively displaced by a predetermined angular increment from one another, and

(ii) the corresponding members of the adjacent rows of said elements being angularly displaced from one another by 1/2 of said angular increment between the adjacent elements of eachA said row; and

(d) a partition disposed intermediate the ends of the inner housing and separating a first, inlet section of such housing adjacent the inlet end thereof, from a second, outlet section adjacent the outlet end thereof, the aggregate cross-sectional area of the conduit elements extending through the walls of said inlet section being substantially equal to the cross-sectional area of the inlet endl of said inner housing;

such that a plurality of miscible fluids fed into said inlet end ow through the inlet section longitudinally thereof, through the conduit ^elements extending through the walls of the inlet section and into the annular region, creating a first, substantially homogeneous helical uid flow pattern therein; through the conduit `elements extending through the walls of the outlet section into such section, creating a second, substantially homogeneous helical flow pattern therein having a reverse sense from that produced in said annular region; and ow through the outlet section to the outlet end thereof.

2. A device for mixing vaporous materials, which comprises:

(a) an elongated generally cylindrical inner housing,

having a iirst inlet and a second outlet end;

(b) an elongated outer housing having a generally cylindrical section extending co-axially of the inner housing lengthwise of the major portion thereof and terminating in frustoconical sections, at its opposite ends secured tto the outer walls of the inner housing, an annular region being defined between the inner and outer housings;

(c) a plurality of rows of transversely oriented hollow pipe sections, mounted on and extending through the walls of the inner housing, each of said pipe sections communicating at its inner end with the interior of the inner housing and at its outer end with, said annular region,

(i) each of said rows of transversely oriented pipe sections comprising a number of such sections Whose axes are substantially co-planar and which pipe sections are successively displaced by a predetermined angular increment from one another, the axis of each said section being angularly displaced from the imaginary point of intersection, on the outer surface of the inner housing, of such axis and a radius of said inner housing;

(ii) the corresponding members of the adjacent rows of said pipe sections being angularly displaced from one another by 1/2 the angular increment between the adjacent pipe sections of each said row; and

(d) `a solid partition mounted transversely of the inner housing and intermediate the ends thereof to separate said inner housing into a rst inlet section adjacent the inlet end thereof, and a second outlet section adjacent the outlet end thereof, the aggregate cross-sectional area ofthe conduit elements extending through the walls of said inlet section being substantially equal to the cross-sectional area of the inlet end of said inner housing;

said partition, the angular displaced pipe sections in each of said rows of pipe sections, and the successive rows of said plurality being so arranged that a plurality of miscible vapors fed longitudinally of and into the inlet end of the inner housing flow through the inlet section; through the pipe sections extending through the walls of said inlet section into sai-d annular region, to produce a substantially homogeneous helical ow pattern therein; and subsequently pass through the pipe sections extending through the walls of the outlet section of said inner housing into said outlet section, to produce a substantially homogeneous helical flow pattern reversed from that produced in said annular region, the vapor mixture thus formed flowing outwardly ofthe device.

3. An apparatus for mixing ammonia Vapor and air, substantially as deiined in claim 1, in which the axis of each 0f said pipe pieces is angularly displaced 45 from the imaginary point of intersecit'ion, on the outer surface of the inner housing, of lsuch axis and a radius of said inner housing; in which the axes of the individual pipe sections of each of said rows of such sections are angularly displaced 72 from one :another to provide 5 pipe sections, equi-spaced -an'gularly of said inner housing, in each of said rows; and in which said rows comprise alternated sets, the pipe sections of lthe second `of which sets are angularly displaced 36 from the corresponding pipe section 0f the lirst of which sets.

References Cited by the Examiner UNITED STATES PATENTS 2,740,616 4/56 Walden 259-4 30 CHARLES A. WILLMUTH, Primary Examiner. 

1. A FLUID MIXING DEVICE, WHICH COMPRISES: (A) AN ELONGATED INNER HOUSING, HAVING A FIRST INLET END AND A SECOND OUTLET END; (B) AN ELONGATED OUTER HOUSING ENCLOSING AT LEAST A PORTION OF THE INNER HOUSING TO DEFINE AN ANNULAR REGION THEREBETWEEN; (C) A PLURALITY OF ROWS OF TRANSVERSELY ORIENTED HOLLOW CONDUIT ELEMENTS MOUNTED ON AND EXTENDING THROUGH THE WALLS OF THE INNER HOUSING, EACH OF SAID ELEMENTS COMMUNICATING AT ITS INNER END WITH THE INTERIOR OF THE INNER HOUSING AND AT ITS OUTER END WITH SAID ANNULAR REGION, (I) EACH OF SAID ROWS COMPRISING A NUMBER OF SAID ELEMENTS WHOSE AXES ARE SUBSTANTIALLY CO-PLANAR AND WHICH ARE SUCCESSIVELY DISPLACED BY A PREDETERMINED ANGULAR INCREMENT FROM ONE ANOTHER, AND (II) THE CORRESPONSING MEMBERS OF THE ADJACENT ROWS OF SAID ELEMENTS BEING ANGULARLY DISPLACED FROM ONE ANOTHER BY 1/2 OF SAID ANGUALR INCREMENT BETWEEN THE ADJACENT ELEMENTS OF EACH SAID ROW; AND (D) A PARTITION DISPOSED INTERMEDIATE THE ENDS OF THE INNER HOUSING AND SEPARATING A FIRST, INLET SECTION OF SUCH HOUSING ADJACENT THE INLET END THEREOF, FROM A SECOND, OUTLET SECTION ADJACENT THE OUTLET END THEREOF, THE AGGREGATE CROSS-SECTIONAL AREA OF THE CONDUIT ELEMENTS EXTENDING THROUGH THE WALLS OF SAID INLET SECTION BEING SUBSTANTIALLY EQUAL TO THE CROSS-SECTIONAL AREA OF THE INLET END OF SAID INNER HOUSING; SUCH THAT A PLURALITY OF MISCIBLE FLUIDS FED INTO SAID INLET END FLOW THROUGH THE INLET SECTION LONGITUDINALLY THEREOF, THROUGH THE CONDUIT ELEMENTS EXTENDING THROUGH THE WALLS OF THE INLET SECTION AND INTO THE ANNULAR REGION, CREATING A FIRST, SUBSTANTIALLY HOMOGENEOUS HELICAL FLUID FLOW PATTERN THEREIN; THROUGH THE CONDUIT ELEMENTS EXTENDING THROUGH THE WALLS OF THE OUTLET SECTION INTO SUCH SECTION, CREATING A SECOND, SUBSTANTIALLY HOMOGENEOUS HELICAL FLOW PATTERN THEREIN HAVING A REVERSE SENSE FROM THAT PRODUCED IN SAID ANNULAR REGION; AND FLOW THROUGH THE OUTLET SECTION TO THE OUTLET END THEREOF. 